Polyhaloaromatic ruthenium complexes and reactions thereof

ABSTRACT

Novel ruthenium pi-arene complexes in which the arene ring has 3 or more halogen atoms bound to it are disclosed. These compounds are reacted with phenoxides and thiophenoxides to form ruthenium pi-arene complexes of polyfunctional aromatic ethers and thioethers which are useful as monomers and crosslinking agents.

FIELD OF THE INVENTION

Disclosed herein are novel polyhaloaromatic pi-arene complexes ofruthenium, which can react with phenoxides or thiophenoxides to formpolyfunctional ruthenium complexes. Such complexes are useful ascrosslinking agents in polymerizations.

TECHNICAL BACKGROUND

Ruthenium pi-arene complexes with certain aromatic compounds are known,see for instance R. M. Moriarty, et al., J. Organometal. Chem., vol.350, p. 157-190 (1988). Such complexes in which a benzene ring containsone or two halogen atoms are known (see T. P. Gill et al.,Organometallics, vol. 1, p. 485-488 (1982), and R. M. Moriarty, et al.,ibid). The complexes which contain halogenated benzene rings are alsoknown to undergo nucleophilic substitution reactions with phenoxides orthiophenoxides (R. M. Moriarty, et al., ibid).

However, to Applicant's knowledge, no pi-arene complex of ruthenium hasbeen reported wherein the arene ring contains more than two halogenatoms. Furthermore, there are comments or experiments in the art wheredoubt has been expressed as to whether similar complexes with othermetals (Cr, Fe) which contain 3 or more halogen atoms attached to thearomatic ring can be made, see G. Wilkinson, et al., Ed., ComprehensiveOrganometallic Chemistry, Vol. 3, Pergamon Press, Oxford, 1982, p. 1001;M. E. Wright, Organometallics, vol. 8, p. 407-411 (1989); V. Percec, etal., J. Polym. Sci. A, vol. 31, p. 923-932 (1993); and D. Astruc, Tet.(Tet. Reports No. 157), vol.-39, p. 4027-4095 (see especially p. 4038)(1983).

SUMMARY OF THE INVENTION

This invention concerns a pi-polyhaloarene complex of the formula##STR1## wherein: each R¹ and each R² is independently hydrogen, halogenor R³ ;

R³ is an inert monovalent radical having a Hammett sigma constant whichis greater than -0.35 and less than -0.12;

R⁴ is cyclopentadienyl or pentamethylcyclopentadienyl;

X is perfluoroalkylsulfonate or hexafluorophosphate;

and provided that:

at least three of R¹ and at least three of R² are halogen;

and no more than two of R¹, and no more than two of R², are R³.

This invention also concerns a process for the production of aromaticethers and thioethers, comprising, contacting a pi-polyhaloarene complexof the formula ##STR2## with a second compound of the formula ##STR3##wherein: each R¹ and each R² is independently hydrogen, halogen or R³ ;

R³ is an inert monovalent radical having a Hammett sigma constant whichis greater than -0.35 and less than -0.12;

R⁴ is cyclopentadienyl or pentamethylcyclopentadienyl;

X is perfluoroalkylsulfonate or hexafluorophosphate;

M is an alkali metal cation;

Y is oxygen or sulfur;

each R⁵ is independently hydrogen, halogen, amino, alkyl or alkoxy;

and provided that:

at least three of R¹ and at least three of R² are halogen;

no more than two of R¹, and no more than two of R², are R³ ; and

at least 1 of R⁵ is halogen or amino; and

at least 3 of R⁵ are hydrogen, alkyl or alkoxy.

This invention further concerns a polyfunctional pi-arene complex of theformula ##STR4## wherein: n is 2, 3, 4 or 5;

m is an integer of 2 through 7;

p and q are independently an integer of 1 through 4;

each R⁵ and each R⁶ is independently hydrogen, halogen, alkyl, alkoxy oramino;

R⁴ is cyclopentadienyl or pentamethylcyclopentadienyl;

X is perfluoroalkylsulfonate or hexafluorophosphate;

Y is oxygen or sulfur;

each R¹ and each R² is independently hydrogen, halogen or R³ ;

R³ is an inert monovalent radical having a Hammett sigma constant whichis greater than -0.35 and less than -0.12; and

provided that at least one of R⁵ and one of R⁶ is amino or halogen, andat least 3 of R⁵ and 3 of R⁶ are hydrogen, alkyl or alkoxy.

DETAILS OF THE INVENTION

The pi-polyhaloarene complexes (PPAC) disclosed herein are useful in thepreparation of the polyfunctional pi-arene complexes of formulae V, VIand VII which are useful as monomers and crosslinking agents incondensation polymerization. In the formulas for ruthenium pi-arenecomplexes herein, the symbol "→" indicates a ruthenium atom (or cation)coordinated to an arene (aromatic) ring, thus being a pi-arene complex.

Complexes I, II, III, and IV are prepared by reacting the correspondinghaloaromatic with a ruthenium compound which can undergo ligand exchangereactions, i.e., R⁴ Ru (CH₃ CN)₃, SO₃ CF₃. The reaction occurs in arelatively polar solvent, for example tetrahydrofuran, at 60°-80° C. for4-40 hours, see Examples 1, 2, and 3.

In the PPACs of the present invention, the halogen, in R¹ and R², isfluorine, chlorine, bromine, and/or iodine. It is preferred if thehalogen is fluorine, chlorine and/or bromine, more preferred if it isfluorine and/or chlorine, and especially preferred if it is chlorine.More than one type of halogen may be present in a PPAC. It is preferredif 3 or 4 of R¹ and R² attached to each aromatic system are halogen. Ina preferred PPAC R⁴ is pentamethylcyclopentadienyl. In another preferredform, X is perfluoroalkylsulfonate wherein the perfluoroalkyl groupcontains 1 to 8 carbon atoms, and more preferred if X istrifluoromethanesulfonate, "triflate". It is also preferred if R³ isalkyl or alkoxy containing up to 20 carbon atoms. The preferred PPACsdescribed in this paragraph are also preferred in the process for theproduction of aromatic ethers and thioethers.

The group R³ is a group that does not interfere with the formation ofthe ruthenium pi-arene complex or with the nucleophilic substitutionprocess (see below). This group is chosen from those which have Hammettsigma (para) constant of more than -0.35 but less than -0.12, preferablymore than -0.25 and less than -0.17. Examples of R³ are alkyl andalkoxy. Such sigma constants are known to one skilled in the art, seefor instance H. H. Jaffe, Chem. Rev., vol. 53, p. 191-261 (1953),especially Table 7.

The "second compound" of the process to make aromatic ethers orthioethers is a phenoxide or thiophenoxide salt of an alkali metalcation (M⁺). It is preferred if the alkali metal is potassium. In thethiophenoxide or phenoxide it is preferred if, on each ring, one of R⁵is halo or amino and the rest of R⁵ are hydrogen. It is more preferredif, on each ring, one of R⁵ is amino and the other of R⁵ are hydrogen.

The process is preferably carried out in solution, useful solvents beingaprotic (less acidic than phenols and thiophenols) and relatively polar.Suitable solvents include tetrahydrofuran, acetonitrile anddimethylsulfoxide. It is preferred to carry out the process at 25° C. to80° C., more preferably 25° C. to 60° C. Since some of the reactants aresensitive to water and/or oxygen, it is preferred to carry out theprocess under a dry inert gas such as nitrogen or argon. The ingredientsare preferably mixed initially, and it is preferred to agitate theprocess gently. The process may be carried out so that one, some or allof the halogen atoms in the PPAC are reacted in the process. When all ofthe halogen atoms are not reacted, some of the halogen atoms originallycontained in the starting PPAC will be present in the product.

The product of the process is a polyfunctional pi-arene complex offormulae V, VI and VII. In the polyfunctional pi-arene complex it ispreferred that n is 3 or 4, that m is 3 or 4, and that p and q are eachindependently 2 or 3. It is also preferred that one of R⁵ and one of R⁶in each ring is halogen or amino, more preferred that it is amino, andall of the remaining R⁵ and R⁶ are hydrogen. It is preferred that all ofR¹ and all of R² are hydrogen.

In the following Examples, Cp* is pentamethylcyclopentadieneyl.

EXAMPLE 1

Synthesis of Cp*Ru(1,3,5-trichlorobenzene), SO₃ CF₃ ##STR5##

A 100 mL Schlenk flask was charged with 1,3,5-trichlorobenzene (1.64 g,9.05 mmol, 15% excess) and Cp*Ru(CH₃ CN)₃, SO₃ CF₃ (4.00 g, 7.87 mmol)in THF (70 mL). The reaction was stirred and heated at reflux for 16 h.Addition of diethyl ether (45 mL) to the solution precipitated a whitesolid that was isolated by filtration and washed twice with 10 mL ofether and dried in vacuo.

¹ H NMR (d₆ -DMSO): 7.21 (s, 3H, arene), 1.88 (s, 15H, CH3) ppm; ¹³ CNMR (d₆ -DMSO): 102.5, 98.7, 89.1, 8.5 ppm; MS (positive FAB) calcd m/zcation 417, found m/z 417; Anal. Calcd for C₁₇ H₁₈ Cl₃ RuSO₃ F₃ : C,36.02, H, 3.20. Found: C, 35.89, H, 3.12. Yield: 72.5%.

EXAMPLE 2 Synthesis of Cp*Ru(1,2,4,5-tetrachlorobenzene), SO₃ CF₃##STR6##

The procedure was the same as described for Example 1 but using ca. 30%excess 1,2,4,5-tetrachlorobenzene.

1H NMR (d₆ -DMSO): 7.66 (s, 2H, arene), 1.82 (s, 15H, CH3) ppm; ¹³ C NMR(d₆ -DMSO): 130.2, 99.3, 88.5, 8.0 ppm; MS (positive FAB) calcd m/zcation 450.9, found m/z cation 450.9; Anal. Calcd for C₁₇ H₁₇ Cl₄ RuSO₃F₃ : C, 33.96, H, 2.85. Found: C, 33.83, H, 2.66. Yield: 78%.

EXAMPLE 3 Synthesis of Cp*Ru(Hexachlorobenzene), SO₃ CF₃ ##STR7##

A 100 mL Schlenk flask was charged with hexachlorobenzene (1.40 g, 4.93mmol, 2.5 equiv) and Cp*Ru (CH₃ CN)₃, SO₃ CF₃ (1.0 g, 1.97 mmol) indioxane (25 mL) or diglyme (25 mL). The reaction mixture was stirred andheated at 80° C. for 3 days. After cooling the reaction mixture to 25°C. the solids that precipitated were collected by filtration and washedwith toluene (3×50 mL) to remove excess unreacted hexachlorobenzene. Theremaining solids were collected and dried in vacuo.

¹ H NMR (d₆ -DMSO): 1.65 (s, CH3); ¹³ C NMR (d₆ -DMSO): 104.0, 100.8,7.2 ppm; MS (positive FAB) calcd m/z cation 519, found m/z cation 519;Anal. Calcd for: C, 30.47, H, 2.26. Found: C, 30.42, H, 2.14.

EXAMPLE 4 Synthesis of Cp*Ru(1,3,5-tris (4-aminophenoxy)benzene), SO₃CF₃ ##STR8##

A 100 mL Schlenk flask charged with Cp*Ru(1,3,5-trichlorobenzene), (SO₃CF₃) (0.30 g, 0.53 mmol) and potassium p-aminophenoxide (0. 257 g, 1.75mmol) in acetonitrile (20 mL) was stirred at 25° C. for 1 h. To ensurecomplete substitution, the reaction was warmed at 60° C. for 1 h. Thesolvent was removed in vacuo, the residue was dissolved in methylenechloride (15 mL), extracted with water (2×20 mL), and the organic layerwas dried over MgSO₄. After filtration, the solvent was removed in vacuoand the residue was dissolved in acetonitrile (5-10 mL). Addition ofdiethyl ether (15 mL) precipitated a white solid that was isolated byfiltration and dried in vacuo.

¹ H NMR (d₆ -DMSO): 6.86 (d, J=8.9 Hz, 6H, Ar H), 6.56 (d, J=8.9 Hz, 6H,Ar H), 5.79 (s, 3H, arene), 1.92 (s, 15H, CH3) ppm; ¹³ C NMR (d₆ -DMSO):146.6, 143.9, 129.0, 120.3, 114.7, 94.9, 68.8, 10.0 ppm; MS (positiveFAB) calcd m/z cation 636.2, found m/z cation 636.2; Anal. Calcd for C₃₅H₃₆ N₃ O₆ SF₃ Ru: C, 53.57, H, 4.62, N, 5.35. Found: C, 53.02, H, 4.41,N, 5.29.

EXAMPLE 5 Synthesis of Cp*Ru (1,2,4,5-tetrakis (4-aminophenoxy)benzene),SO₃ CF₃ ##STR9##

The procedure is the same as described for Example-4 usingCp*Ru(1,2,4,5-tetrachlorobenzene), SO₃ CF₃ and potassium4-aminophenoxide in acetonitrile solvent.

¹ H NMR (d₆ -DMSO): 6.88 (d, J=8.9 Hz, 8H, Ar H), 6.53 (d, J=8.9 Hz, 8H,Ar H), 5.94 (s, 2H, arene), 1.91 (s, 15H, CH3) ppm; ¹³ C NMR (d₆ -DMSO):145.8, 118.9, 118.0, 114.6, 95.4, 73.0, 9.5 ppm; MS (positive FAB) calcdm/z cation 743; found m/z cation 743; Anal. Calcd for C₄₁ H₄₁ O₇ SN₄ F₃Ru: C, 55.21, H, 4.63, N, 6.28. Found: C, 54.02, H, 4.16, N, 6.14.

EXAMPLE 6 Synthesis of Cp*Ru (1,3,5-tris (4-chlorophenoxy)benzene), SO₃CF₃ ##STR10##

The procedure is the same as described for Example 4 using potassium4-chlorophenoxide in acetonitrile solvent.

¹ H NMR (d₆ -DMSO): 7.53 (d, J=9.1 Hz, 6H, Ar H), 7.30 (d, J=9.1 Hz, 6H,Ar H), 6.49 (s, 3H, arene), 1.96 (s, 15H, CH3) ppm; ¹³ C NMR (d₆ -DMSO):154.4, 129.9, 128.6, 125.8, 119.9, 96.5, 73.9, 9.5 ppm; MS (positiveFAB) calcd m/z cation 693, found m/z cation 693; Anal. Calcd for C₃₅ H₃₀O₆ SCl₃ F₃ Ru: C, 49.86, H, 3.56. Found: C, 49.61, H, 3.27.

EXAMPLE 7 Synthesis of Cp*Ru (1,2,4,5-tetrakis(4-chlorophenoxy)benzene), SO₃ CF₃ ##STR11##

The procedure is the same as described for Example 4 using Cp*Ru(1,2,4,5-tetrachlorobenzene), SO₃ CF₃ and potassium 4-chlorophenoxide inacetonitrile solvent.

¹ H NMR (d₆ -DMSO): 7.44 (d, J=9.1 Hz, 8H, Ar H), 7.31 (d, J=9.1 Hz, 8H,Ar H), 7.00 (s, 2H, arene), 1.97 (s, 15H, CH3) ppm; ¹³ C NMR (d₆ -DMSO):154.9, 129.6, 128.2, 118.7, 117.5, 97.3, 76.6, 9.1 ppm; MS (positiveFAB) calcd m/z cation 819; found m/z cation 819; Anal. Calcd for C₄₁ H₃₃O₇ SCl₄ F₃ Ru: C, 50.79, H, 3.43. Found: C, 50.23, H, 3.36.

EXAMPLE 8 Synthesis of Cp*Ru (1,3,5-tris (4-fluorophenoxy)benzene), SO₃CF₃ ##STR12##

The procedure is the same as described for Example 4 using potassium4-fluorophenoxide in acetonitrile solvent.

¹ H NMR (d₆ -DMSO): 7.32-7.29 (m, 12H, Ar H), 6.32 (s, 3H, arene), 1.96(s, 15H, CH3) ppm; ¹³ C NMR (d₆ -DMSO): 158.9 (d, ¹ J_(CF) =241.2 Hz),151.6, 126.7, 120.3 (d, ³ J_(CF) =8.6 Hz), 116.9 (² J_(CF) =23.7 Hz),96.3, 72.9, 9.7 ppm; MS (positive FAB) calcd m/z cation 645, found m/zcation 645; Anal. Calcd for C₃₅ H₃₀ O₆ SF₆ Ru: C, 52.96, H, 3.81. Found:C, 52.95, H, 3.19.

What is claimed is:
 1. A pi-polyhaloarene complex of the formula##STR13## wherein: each R¹ and each R² is independently hydrogen,halogen R³ ;R³ is an inert monovalent radical having a Hammett sigmaconstant which is greater than -0.35 and less than -0.12; R⁴ iscyclopentadienyl or pentamethylcyclopentadienyl; X isperfluoroalkylsulfonate or hexafluorophosphate;and provided that: atleast three of R¹ and at least three of R² are halogen; and no more thantwo of R¹, and no more than two of R², are R³.
 2. The pi-polyhaloarenecomplex as recited in claim 1 wherein said halogen is independentlyselected from the group consisting of fluorine, chlorine, and bromine.3. The pi-polyhaloarene complex as recited in claim 2 wherein saidhalogen is independently selected from the group consisting of fluorineand chlorine.
 4. The pi-polyhaloarene complex as recited in claim 3wherein said halogen is chlorine.
 5. The pi-polyhaloarene complex asrecited in claim 1 wherein R³ is an inert monovalent radical having aHammett sigma constant which is greater than -0.25 and less than -0.17.6. The pi-haloarene complex as recited in claim 5 wherein R³ is selectedfrom the group consisting of alkyl and alkoxy.
 7. The pi-haloarenecomplex as recited in claim 1 wherein R⁴ ispentamethylcyclopentadienide.
 8. The pi-haloarene complex as recited inclaim 1 wherein X is perfluoroalkylsulfonate wherein the perfluoroalkylgroup contains 1-8 carbon atoms.
 9. The pi-haloarene complex as recitedin claim 8 wherein X is trifluoromethanesulfonate.
 10. Thepi-polyhaloarene complex as recited in claim 1 of the formula ##STR14##wherein R⁴ is pentamethylcyclopentadienyl.
 11. The pi-polyhaloarenecomplex as recited in claim 1 of the formula ##STR15## wherein R⁴ ispentamethylcyclopentadienyl.